aboutsummaryrefslogtreecommitdiffstats
path: root/core/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'core/time.c')
-rw-r--r--core/time.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/core/time.c b/core/time.c
new file mode 100644
index 0000000..164d978
--- /dev/null
+++ b/core/time.c
@@ -0,0 +1,72 @@
+/* *****************************************************************************
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Created: 12/18/09 02:41:36
+ * Copyright (c) 2009 Perry L. Hung. All rights reserved.
+ *
+ * ****************************************************************************/
+
+/**
+ * @file time.c
+ *
+ * @brief
+ */
+
+#include "libmaple.h"
+#include "systick.h"
+#include "time.h"
+
+#define CYCLES_PER_MICROSECOND 72
+#define FUDGE 42
+
+extern volatile uint32_t systick_timer_millis;
+
+unsigned long millis() {
+ unsigned long m;
+ m = systick_timer_millis;
+ return m;
+}
+
+void delay(unsigned long ms)
+{
+ unsigned long start = millis();
+
+ while (millis() - start <= ms)
+ ;
+}
+
+
+
+#if 1
+void delayMicroseconds(uint32_t us) {
+ uint32_t target;
+ uint32_t last, cur, count;
+ /* fudge factor hacky hack hack for function overhead */
+ target = us * CYCLES_PER_MICROSECOND - FUDGE;
+
+ /* Get current count */
+ last = systick_get_count();
+ cur = systick_get_count();
+ count = last;
+ while ((count-cur) <= target) {
+ cur = systick_get_count();
+
+ /* check for overflow */
+ if (cur > last) {
+ count += MAPLE_RELOAD_VAL;
+ }
+ last = cur;
+ }
+}
+#endif